//
// Copyright 2022 SkyAPM org
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

package tool

import (
	"net"
	"os"
	"runtime"
	"strconv"
)

// ProcessNo pid
func ProcessNo() string {
	if os.Getpid() > 0 {
		return strconv.Itoa(os.Getpid())
	}
	return ""
}

// HostName hostname
func HostName() string {
	if hs, err := os.Hostname(); err == nil {
		return hs
	}
	return "unknown"
}

// OSName os name
func OSName() string {
	return runtime.GOOS
}

// AllIPV4 all ipv4
func AllIPV4() (ipv4s []string) {
	adders, err := net.InterfaceAddrs()
	if err != nil {
		return
	}

	for _, addr := range adders {
		if ipNet, ok := addr.(*net.IPNet); ok && !ipNet.IP.IsLoopback() {
			if ipNet.IP.To4() != nil {
				ipv4 := ipNet.IP.String()
				if ipv4 == "127.0.0.1" || ipv4 == "localhost" {
					continue
				}
				ipv4s = append(ipv4s, ipv4)
			}
		}
	}
	return
}

// IPV4 ipv4
func IPV4() string {
	ipv4s := AllIPV4()
	if len(ipv4s) > 0 {
		return ipv4s[0]
	}
	return "no-hostname"
}
